The way the matches are set up it is important not to lose the standard time game and put all your effort into the blitz. Therefore they play very safely and save their novelties for the blitz. If you look at the blitz games you will find 1.e4.

The way the matches are set up it is important not to lose the standard time game and put all your effort into the blitz. Therefore they play very safely and save their novelties for the blitz. If you look at the blitz games you will find 1.e4.

Strangely though, it does seem to make some sense. If you are caught with something you don't know in blitz, you might either make a really bad move early, or get into time pressure right away, either of which could be quite costly (perhaps this is what happened to Caruana in his blitz tiebreak game against Magnus -- if Caruana saw Magnus's line in a classical game, surely he wouldn't blunder like that). Although in tournaments they occasionally do blitz, I think in matches ties are decided by rapid games, but still, that's not super long.

Besides, it looks like the players of the current Candidates (for example) prefer 1.d4 personnally. Maybe than in 30 years time, the strongest players would have a personal preference towards 1.e4 (and people will complain that d4 is dead).